It doesn't matter if it's tied to gold or not. It's simple supply and demand. Excess supply with lower or same demand is a decrease in value. If all you had are apples and dollars, if you have 10 apples and 10 dollars, each apple is worth 1 dollar. If you increase the money supply to 1000 dollars, then each apple is worth 100 dollars.
You forget the wonders of Capitalism; if the money supply increases, then companies will increase supply to meet the increased demand, since they are in the business of making money. Sure, if people were "willing" to spend 100 dollars on an apple then maybe you'd have a point, but what would happen instead of either:
a: Demand falling off a cliff due to the increased price
b: People would start growing apples themselves
c: The producer of said apples would invest an some more apple trees.
Obviously, C is what would occur; apple production would increase, and apples would continue to sell for around 1 dollar apiece. Your argument falls apart because you don't believe businesses are ruthlessly capitalistic.
In theory. What does negative interest rates tell you?
And based on the amount of money printed last year, that 2%... Yeah... Unrealistic. It's only been kept in check due to lockdowns. When that lifts... Prepare for trouble.
Negative interest rates are just a way to entice consumers (especially those who are higher earners) to spend more money, since it literally costs them money not to. This has only really been done once (Europe, tail end of the Great Recession), and guess what? No runaway inflation. Because once consumer spending recovered and inflation started to rise interest rates went back up to discourage as much spending, restoring balance.
What will ultimately happen if we'll get a few quarters of 5-6% economic growth, and a short term burst of inflation (likely localized to a few industries who are production constrained (see: any product that needs a CPU). Then inflation rates will rise, inflation will taper off, and we'll go right back to complaining who's fault it is we can't grow the economy faster then 2.5%.
At the end of the day, history proves your argument is wrong. Raegan spent like a drunken sailor, and high inflation was tamed under his administration (mostly due to Volcker rather then anything Raegan did). Same with Clinton. And Obama. And Trump. And inflation has remained at the Feds 2% target, and has done so since the Fed has made it's focus to keep inflation stable. If anything, the fear of inflation has cost economic growth as the Feds have been notoriously slow to decrease interest rates in response to a slowing economy.